The present invention relates to the food processing arts. It finds particular application in conjunction with the post-pasteurization, surface microbial decontamination of hot dogs, sausages, and other processed meat and poultry products prior to packaging, and will be described with particular reference thereto. It should be appreciated, however, that the invention is also applicable to the treatment of raw meat and poultry and other food products subject to microbial contamination.
Prevention of food poisoning is of paramount importance in the food processing industry. Concern for food safety has lead most countries to regulate the food industry heavily to minimize public health risks. Despite these efforts, food poisoning still occurs. Many instances of food poisoning are attributed to bacteria, such as Salmonella, Clostridium, and Staphylococcus, among others.
Of rising concern is the relatively recent increase in the Listeria contamination of poultry and processed food products, such as frankfurters, other sausages, cheese, dairy food, and seafood. Processed meat and poultry products such as frankfurters are generally cooked to destroy harmful bacteria of particular concern is the discovery that pasteurized and fully cooked processed foods are being contaminated with microbes, such as Listeria monocytogenes, following cooking or pasteurization and prior to packaging for point of sale. Such contamination is typically surface contamination and is believed to be caused by the contact of microbes with food surfaces subsequent to heat treatment. Microbes such as Listeria may be airborne (i.e. carried by dust) or present on food contacting surfaces, such as processing equipment.
Recently, several outbreaks of food poisoning have been reported in which the causative agent was suspected to be or identified as Listeria contaminated food. Listeriosis is a serious disease which may cause meningitis, spontaneous abortion, and perinatal septicaemia. Although treatable with early diagnosis, untreated Listeriosis exhibits a high mortality rate. In 1998, 20 deaths were associated with a Listeria epidemic. Regulations now specify that food should be absolutely free of Listeria, any contamination is. considered to be an adulteration and the food should not be placed in commerce.
Food preservation by inhibition of growth of Listeria monocytogenes is difficult. Listeria is a particularly difficult microorganism to destroy because it is heat resistant and is able to grow even under refrigeration in raw and cooked products. Methods for destroying the organism on raw and on processed foods have included treatments using heat, radiation, chemicals, or antibiotics.
In the heat and irradiation treatments, the food products are subjected to the heat or radiation after packaging. However, the heat resistance of the organism makes it difficult to achieve complete kill through heat.
Antibiotics, such as Streptococcus lactis-derived or synthetic equivalent bacteriocin, such as nisin, have been used, either as a spray, or dip, or as a film on the packaging or casing which remains in contact with the food during heat treatment.
Chemicals used in treating the food products include ammonium compounds and acids such as citric, lactic and acetic acid, which have been used to wash down meat carcasses. With the chemical treatment methods, the carcass is placed on a conveyer system and the decontaminating chemical is sprayed over the items as they pass beneath. Liquid smoke has been used on pasteurized processed foods to inhibit recontamination after cooking. However, this imparts an undesirable, phenolic taste when used post-pasteurization.
If chemicals are to be used post-pasteurization, it is desirable that they are both effective antimicrobial agents and non-hazardous to consumers if they remain on the food product. Acids such as citric, lactic and acetic acids, while being safe for consumers, are not always completely effective at inactivating the microorganism. Even if one or two microorganisms remain on the food product, these can grow and multiply under refrigeration to a level to which they are toxic to the consumer by the time the product is sold.
The present invention provides for a new and improved apparatus and method for treating food products which overcomes the above-referenced problems and others.
In accordance with one aspect of the present invention, a method of treating a food product is provided. The method includes contacting an exterior of the food product with a decontaminant solution containing an antimicrobial agent, which includes peracetic acid, for a sufficient time to microbially decontaminate the exterior of the food product.
In accordance with another aspect of the present invention, a method of treating a food product is provided. The method includes spraying the food product with a solution comprising peracetic acid in a first chamber and drying the food product in a second chamber.
In accordance with another aspect of the present invention, an apparatus for treatment of a food product is provided. The apparatus includes first and second chambers. Spray nozzles are disposed in the first chamber for spraying a decontaminant solution over the food product. The decontaminant solution includes peracetic acid. A pump is fluidly connected with a source of the decontaminant solution and the nozzles for supplying pressurized decontaminant solution to the nozzles. A source of a drying gas is connected with the second chamber for drying the decontaminated food product. A conveyor system conveys the food product through the first and second chambers.
One advantage of the present invention is that pathogenic bacteria, such as Listeria, E. coli, and Salmonella are destroyed in a short period of time.
Another advantage of the present invention is that the peracetic acid used to decontaminate the food products naturally degrades to non-harmful reaction products, such as acetic acid and water, over a short period of time.
Still further advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiments.